Thank you for reaching out to Constant Contact's API Support.
I'm not an expert with python, but it looks like your for loop is iterating each line in the result as a string instead of as JSON data. Python supports JSON natively so you should be able to just call in something to do this for you.
I did a quick internet search and found a few resources. I personally liked the Hitchhikers guide to Python, but I may be biased to that reference.